Triple, Mutually Orthogonal Bioorthogonal Pairs through the Design of Electronically Activated Sulfamate-Containing Cycloalkynes

J Am Chem Soc. 2020 Nov 4;142(44):18826-18835. doi: 10.1021/jacs.0c06725. Epub 2020 Oct 21.

Abstract

Interest in mutually exclusive pairs of bioorthogonal labeling reagents continues to drive the design of new compounds that are capable of fast and predictable reactions. The ability to easily modify S-, N-, and O-containing cyclooctynes (SNO-OCTs) enables electronic tuning of various SNO-OCTs to influence their cycloaddition rates with Type I-III dipoles. As opposed to optimizations based on just one specific dipole class, the electrophilicity of the alkynes in SNO-OCTs can be manipulated to achieve divergent reactivities and furnish mutually orthogonal dual ligation systems. Significant reaction rate enhancements of a difluorinated SNO-OCT derivative, as compared to the parent scaffold, were noted, with the second-order rate constant in cycloadditions with diazoacetamides exceeding 5.13 M-1 s-1. Computational and experimental studies were employed to inform the design of triple ligation systems that encompass three orthogonal reactivities. Finally, polar SNO-OCTs are rapidly internalized by mammalian cells and remain functional in the cytosol for live-cell labeling, highlighting their potential for diverse in vitro and in vivo applications.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Cycloaddition Reaction
  • Cycloparaffins / chemistry*
  • Fluorescent Dyes / chemistry
  • Microscopy, Fluorescence
  • Molecular Conformation
  • Nitrogen / chemistry
  • Oxygen / chemistry
  • Sulfonic Acids / chemistry*
  • Sulfur / chemistry
  • Thermodynamics

Substances

  • Cycloparaffins
  • Fluorescent Dyes
  • Sulfonic Acids
  • Sulfur
  • sulfamic acid
  • Nitrogen
  • Oxygen